Gabriel Reina

Background/Objectives: Hepatitis B remains a major public health concern in the Democratic Republic of the Congo (DRC). This study investigated HBV seroprevalence in Kinshasa and evaluated the diagnostic performance of rapid diagnostic tests (RDTs) compared with dried blood spot (DBS)–based immunoassays. Methods: DBS samples collected between 2016 and 2022 were transported to Spain for HBsAg and HBc-Ab testing using two chemiluminescence platforms (ECLIA-COBAS (Roche) and ELFA-miniVIDAS (bioMerieux)). A subset of participants also underwent on-site HBsAg screening using Determine™ (Abbott) RDTs. Results: Overall, active HBV infection was detected in 4.3% of participants and resolved infection in 14.3%, with no significant differences by age, sex, cohort, or HIV/HCV status. The RDT showed poor sensitivity (60% (95% CI: 26–88)) but high specificity (100% (95% CI: 98–100)), resulting in a 40% misdiagnosis rate. In contrast, DBS-based HBsAg immunoassays demonstrated excellent diagnostic accuracy, with both platforms achieving 100% sensitivity (ECLIA-COBAS 100%, 95% CI: 66–100; ELFA-miniVIDAS 100%, 95% CI: 99–100) and specificity (ECLIA-COBAS 100%, 95% CI: 98–100; ELFA-miniVIDAS 100%, 95% CI: 99–100). HBc-Ab detection showed platform-dependent variability, with lower sensitivity on ELFA-miniVIDAS (66% (95% CI: 46–82)) compared with ECLIA-COBAS (100% (95% CI: 96–100)). Predictive values were high across all assays, and inter-method agreement for HBsAg between RDT and chemiluminescence was good (Cohen’s kappa 0.71, p < 0.001). Conclusions: These findings indicate moderate HBV transmission in Kinshasa and highlight the limited reliability of RDT-based screening. DBS proved to be a practical, robust, and scalable sampling method with outstanding diagnostic performance, making it well-suited for HBV testing in low-resource settings.

Malnutrition—including undernutrition, micronutrient deficiencies and overweight—remains a major public health concern in sub-Saharan Africa, largely driven by food insecurity. Edible insects have been proposed as a sustainable, nutrient-dense dietary alternative with potential to improve food security and nutritional outcomes. This review analyses studies published until January 2024 in PubMed and Google Scholar assessing the prevalence, acceptability and nutritional impact of insect-based diets in sub-Saharan Africa. Thirteen original studies, predominantly qualitative, conducted in 8 of 47 countries in the region, met inclusion criteria. Two reviews provided additional evidence. Most studies focused on acceptability, which was strongly influenced by cultural and religious norms. Higher acceptance was observed among older individuals and those with lower educational attainment, while younger and more urbanized populations showed greater reluctance. Reported motivations for consumption included tradition, taste and perceived nutritional value. Some studies highlighted potential health risks related to food safety and the need for improved regulatory frameworks. The available nutritional analyses showed that edible insects are rich in protein and essential micronutrients, particularly iron and zinc, suggesting their potential to address common deficiencies. Although evidence on long-term nutritional impact remains limited, current findings support the feasibility and potential public health relevance of promoting insect-based diets in low-income settings.

A microsporidian species, Glugea sp., was identified infecting the visceral cavity of commercial sardines (Sardina pilchardus) from an Atlantic fishery. Macroscopic examination revealed a white, friable mass that readily disintegrates, releasing spherical to ovoid microsporidian spores. Ultrastructural analysis shows an isofilar polar tube with 10–15 coils arranged in one to three rows. The study combined macrophotography, light microscopy, histological staining, transmission electron microscopy (TEM), and molecular analyses. Morphologically, Glugea sp. shares some features with Glugea vincentiae; however, molecular data do not support a close phylogenetic relationship between these two species. Phylogenetic analysis based on 18S rRNA sequences places the organism within a clade comprising G. plecoglossi, G. thunni, G. atherinae, G. gasterostei, G. hertwigi and G. anomala. Despite the high sequence similarity observed within this group, morphological and ultrastructural characteristics allowed differentiation of the present species, highlighting the limitations of relying solely on conserved molecular markers for species delimitation. A comprehensive morphological and molecular description of Glugea sp. is provided. Given the ecological and economic relevance of microsporidia, as well as their recognized role in animal and human disease, this new host–parasite association may have implications for fisheries and food safety, particularly considering the widespread consumption of sardines.

Cervical cancer remains a major public health concern, particularly in low- and middle-income countries (LMICs) where access to preventive measures is limited. Persistent infection with high-risk human papillomavirus (HPV) types, mainly HPV16 and HPV18, is the key cause of cervical cancer. While prophylactic HPV vaccines effectively prevent new infections, they offer no therapeutic benefit for individuals with established lesions. This review evaluates the clinical evidence on therapeutic HPV vaccines, focusing on their ability to promote viral clearance. A bibliographic search was conducted in PubMed, selecting human studies reporting outcomes on HPV clearance. Seventeen clinical trials were identified, including DNA-based (VGX-3100, GX-188E), viral-vector (MVA E2, TG4001), peptide-based (Pepcan), and bacterial-vector (GLT 001) vaccines. Among them, DNA-based vaccines, particularly VGX-3100, showed the most consistent results, whereas several protein- or vector-based approaches demonstrated variable outcomes. Early therapeutic HPV vaccine trials faced setbacks due to limited efficacy, delivery approaches, and study design challenges, preventing progression to late-phase development. Recent DNA-based candidates, however, are advancing through phase II/III trials. While none have yet to be approved for commercial use, these vaccines elicit virus-specific T-cell responses and can induce regression of precancerous lesions, offering a promising addition to prophylactic vaccination and screening. Variability in study designs and endpoints underlines the need for standardized protocols and further phase III trials. Overall, therapeutic HPV vaccines represent a rapidly advancing field with the potential to complement prophylactic vaccination and screening, thereby strengthening global cervical cancer control efforts, particularly in LMICs.

While nutrition is often considered a protective factor against cancer, there is a scarcity of strong, conclusive evidence supporting its direct impact on cervical cancer (CC) prevention. This study aims to review the existing literature on the relationship between women’s nutrition and infection by the human papillomavirus (HPV) and the development of CC. It explores the key nutrients, foods, and dietary patterns that may influence the onset and progression of this disease, including research carried out in sub-Saharan Africa, other low-income countries, and worldwide. The review process revealed that, despite the large initial pool of articles, the majority were excluded because they were not focused on nutrition and CC. However, the articles that met the inclusion criteria suggested an association between diet and lower susceptibility to persistent HPV infections, which could progress into cervical lesions or cancer. Notably, lower folate intake was associated with up to a nine-fold higher risk of CIN3+ lesions (OR 8.9, 95% CI 3.4–24.9), while increased consumption of certain vitamins and antioxidant-rich foods consistently correlated with lower HPV persistence and progression. These results could indicate that consuming antioxidant compounds, certain vitamins, dietary patterns, and functional foods may offer protective benefits against developing this disease and its progression. By emphasizing nutrition as a modifiable factor, this review seeks to raise awareness and propose a holistic approach to CC prevention—integrating public health, dietary considerations, and equity-driven strategies.

The emergence of new variants and diverse vaccination regimens have raised uncertainty about vaccine effectiveness against SARS-CoV-2. This study aims to investigate the impact of Omicron primo-/reinfection and primary vaccination schedules on the immunogenicity of an mRNA-based booster dose over a six-month period. We conducted a prospective cohort study to assess the durability and level of antibodies of 678 healthcare workers fully vaccinated against COVID-19. They were categorized based on their primary vaccination regimen. Blood samples were collected before the booster dose and 1 and 6 months after. Significant Anti-S-RBD differences were found between previously infected and naïve volunteers (p = 0.01). Considering the initial vaccine schedules, mRNA-based vaccines displayed significant higher antibody production and longer persistence among both infected and naïve participants. After the booster dose, participants primoinfected with the Omicron variant exhibited higher antibody concentrations than those who experienced reinfection, even after 6 months of follow-up (22,545 and 9460 U/mL, respectively). Moreover, these groups showed the most pronounced disparity in antibody titers ratios between infected and uninfected individuals. Overall, the booster dose failed to enhance humoral response in individuals reinfected with the Omicron variant after receiving it. Hybrid immunity and mRNA-based vaccine initial schedules showed higher levels and longer persistence of antibodies.

Background/Objectives: The emergence of the Omicron variant has complicated COVID-19 control and prompted vaccine updates. Recent studies have shown that a fourth dose significantly protects against infection and severe disease, though long-term immunity data remain limited. This study aimed to assess Anti-S-RBD antibodies and interferon-γ levels in healthcare workers 12 months after receiving bivalent Original/Omicron BA.4-5 fourth SARS-CoV-2 vaccine. Methods: In this prospective cohort study, 549 healthcare workers were categorized by the initial vaccination schedule, with 229 individuals having received the fourth SARS-CoV-2 vaccine dose. Blood samples were collected from all participants 12 months post-vaccination. Results: Significant differences in Anti-S-RBD antibody levels were observed between those receiving a fourth dose and those who did not, while no differences were seen in interferon-γ levels. After 12 months, there were no significant differences in humoral and cellular immunity response between volunteers primoinfected or reinfected across different periods by the Omicron variant. A multivariable analysis revealed an association between high antibody levels (>6000 U/mL) and interferon-γ levels (OR: 3.13; 95% CI: 1.3–7.7; p < 0.05). Regarding primary vaccine schedules, participants vaccinated with ChAdOx1 (a single or double dose) had notably lower antibody levels compared to those who received mRNA-based vaccines. Additionally, the study shows a higher frequency of multiple infections among those with a single-dose ChAdOx1 primary schedule (OR: 6.24; 95% CI: 1.25–31.15; p < 0.01). Conclusions: Overall, mRNA-based vaccines exhibited stronger long-term immunogenicity. Repeated exposure to the Omicron variant seems to mitigate immune imprinting from the wild-type SARS-CoV-2. An association was observed between high antibody levels and a strong cellular response, although the correlation was not linear.

Background: Dried blood spots (DBSs) enable the study of serological markers of various pathogens without the need to obtain serum/plasma through venipuncture. Methods: Sixty-four blood samples were prepared on Whatman™ 903 cards using specimens obtained by venipuncture to study the detection of serological markers of diphtheria, tetanus, and pertussis in DBSs, and their stability 4 months post-collection. An automated chemiluminescent immunoassay was used to investigate diphtheria, tetanus, and pertussis IgG levels from both DBSs and plasma samples. Results: An optimal cut-off value for DBSs was calculated to improve the performance of diphtheria and tetanus serological markers in DBSs, achieving high sensitivity (95% and 98%, respectively) and specificity (91.7% and 92.3%, respectively). No protection against pertussis was found in the population studied. The correlation observed between the plasma and the DBSs processed after sample collection was high (0.967–0.970) for all antibodies studied except pertussis (0.753), both considering hematocrit before sample elution or not. The correlation between DBSs and plasma for diphtheria and tetanus remained strong following a 4-month delay in DBS processing at 4 °C (0.925–0.964) and −20 °C (0.924–0.966), with only a minor decrease observed for diphtheria at room temperature (0.889), while maintaining a strong correlation for tetanus (0.960). For pertussis, the correlation between DBSs and plasma was drastically reduced after delaying its processing for 4 months at any temperature. Conclusions: To summarize, hematocrit levels within the normal range do not affect the processing of DBSs in the study of serological markers of diphtheria, tetanus, and pertussis. The DBS stability for serological diagnosis of diphtheria and tetanus is adequate when samples are stored at −20 °C for a period of 4 months. The pertussis serological marker does not appear to remain stable after 4 months, even when the DBS is stored frozen at −20 °C.